Description : Jan. 19 2018. - A United Launch Alliance Atlas V rocket will launch the fourth Geostationary Satellite of the Space-Based Infrared for the United States Air Force. This launch will mark the completion of the fully operational SBIRS constellation with four satellites in Geostationary Orbit and at least a pair of functional hosted payloads on satellites in Highly Elliptical Orbits to provide global missile warning and tracking capability via staring and scanning sensors installed on each satellite, capable of detecting infrared signatures of Intercontinental Ballistic Missiles as well as the much fainter signatures of short -range missiles. Atlas V AV-076 will fly in the 411 configuration with one Solid Rocket Boosters, using a more-powerful than previous SBIRS missions to provide sufficient margin for the deorbitation of the Centaur upper stage.